# coding=utf-8
# Copyright 2024 The Google Research Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Functions to manipulate measures."""

import gin
import tensorflow.compat.v2 as tf


@gin.configurable
def kl_divergence(p, q, eps = 1e-20):
  """Computes the generalized KL divergence."""
  return tf.math.reduce_mean(p * tf.math.log((p + eps) / (q + eps)) - p + q)
